Introduce ImmutableCallSite, useful for contexts where no mutation

is necessary. Inherits from new templated baseclass CallSiteBase<>
which is highly customizable. Base CallSite on it too, in a configuration
that allows full mutation.
Adapt some call sites in analyses to employ ImmutableCallSite.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100100 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 160 insertions, 112 deletions

diff --git a/include/llvm/Support/CallSite.h b/include/llvm/Support/CallSite.h
index 480535f..9f527e2 100644
--- a/include/llvm/Support/CallSite.h
+++ b/include/llvm/Support/CallSite.h
@@ -8,15 +8,18 @@
 //===----------------------------------------------------------------------===//
 //
 // This file defines the CallSite class, which is a handy wrapper for code that
-// wants to treat Call and Invoke instructions in a generic way.
+// wants to treat Call and Invoke instructions in a generic way. When in non-
+// mutation context (e.g. an analysis) ImmutableCallSite should be used.
+// Finally, when some degree of customization is necessary between these two
+// extremes, CallSiteBase<> can be supplied with fine-tuned parameters.
 //
-// NOTE: This class is supposed to have "value semantics". So it should be
-// passed by value, not by reference; it should not be "new"ed or "delete"d. It
-// is efficiently copyable, assignable and constructable, with cost equivalent
-// to copying a pointer (notice that it has only a single data member).
-// The internal representation carries a flag which indicates which of the two
-// variants is enclosed. This allows for cheaper checks when various accessors
-// of CallSite are employed.
+// NOTE: These classes are supposed to have "value semantics". So they should be
+// passed by value, not by reference; they should not be "new"ed or "delete"d.
+// They are efficiently copyable, assignable and constructable, with cost
+// equivalent to copying a pointer (notice that they have only a single data
+// member). The internal representation carries a flag which indicates which of
+// the two variants is enclosed. This allows for cheaper checks when various
+// accessors of CallSite are employed.
 //
 //===----------------------------------------------------------------------===//
 
@@ -34,72 +37,42 @@ namespace llvm {
 class CallInst;
 class InvokeInst;
 
-class CallSite {
-  PointerIntPair<Instruction*, 1, bool> I;
+template <typename FunTy = const Function,
+          typename ValTy = const Value,
+          typename UserTy = const User,
+          typename InstrTy = const Instruction,
+          typename CallTy = const CallInst,
+          typename InvokeTy = const InvokeInst,
+          typename IterTy = User::const_op_iterator>
+class CallSiteBase {
+protected:
+  PointerIntPair<InstrTy*, 1, bool> I;
 public:
-  CallSite() : I(0, false) {}
-  CallSite(CallInst *CI) : I(reinterpret_cast<Instruction*>(CI), true) {}
-  CallSite(InvokeInst *II) : I(reinterpret_cast<Instruction*>(II), false) {}
-  CallSite(Instruction *C);
-
-  bool operator==(const CallSite &CS) const { return I == CS.I; }
-  bool operator!=(const CallSite &CS) const { return I != CS.I; }
+  CallSiteBase() : I(0, false) {}
+  CallSiteBase(CallTy *CI) : I(reinterpret_cast<InstrTy*>(CI), true) {}
+  CallSiteBase(InvokeTy *II) : I(reinterpret_cast<InstrTy*>(II), false) {}
+  CallSiteBase(ValTy *II) { *this = get(II); }
+  CallSiteBase(InstrTy *II) {
+    assert(II && "Null instruction given?");
+    *this = get(II);
+    assert(I.getPointer());
+  }
 
-  /// CallSite::get - This static method is sort of like a constructor.  It will
-  /// create an appropriate call site for a Call or Invoke instruction, but it
-  /// can also create a null initialized CallSite object for something which is
-  /// NOT a call site.
+  /// CallSiteBase::get - This static method is sort of like a constructor.  It
+  /// will create an appropriate call site for a Call or Invoke instruction, but
+  /// it can also create a null initialized CallSiteBase object for something
+  /// which is NOT a call site.
   ///
-  static CallSite get(Value *V) {
-    if (Instruction *I = dyn_cast<Instruction>(V)) {
-      if (I->getOpcode() == Instruction::Call)
-        return CallSite(reinterpret_cast<CallInst*>(I));
-      else if (I->getOpcode() == Instruction::Invoke)
-        return CallSite(reinterpret_cast<InvokeInst*>(I));
+  static CallSiteBase get(ValTy *V) {
+    if (InstrTy *II = dyn_cast<InstrTy>(V)) {
+      if (II->getOpcode() == Instruction::Call)
+        return CallSiteBase(reinterpret_cast<CallTy*>(II));
+      else if (II->getOpcode() == Instruction::Invoke)
+        return CallSiteBase(reinterpret_cast<InvokeTy*>(II));
     }
-    return CallSite();
+    return CallSiteBase();
   }
 
-  /// getCallingConv/setCallingConv - get or set the calling convention of the
-  /// call.
-  CallingConv::ID getCallingConv() const;
-  void setCallingConv(CallingConv::ID CC);
-
-  /// getAttributes/setAttributes - get or set the parameter attributes of
-  /// the call.
-  const AttrListPtr &getAttributes() const;
-  void setAttributes(const AttrListPtr &PAL);
-
-  /// paramHasAttr - whether the call or the callee has the given attribute.
-  bool paramHasAttr(uint16_t i, Attributes attr) const;
-
-  /// @brief Extract the alignment for a call or parameter (0=unknown).
-  uint16_t getParamAlignment(uint16_t i) const;
-
-  /// @brief Return true if the call should not be inlined.
-  bool isNoInline() const;
-  void setIsNoInline(bool Value = true);
-  
-  /// @brief Determine if the call does not access memory.
-  bool doesNotAccessMemory() const;
-  void setDoesNotAccessMemory(bool doesNotAccessMemory = true);
-
-  /// @brief Determine if the call does not access or only reads memory.
-  bool onlyReadsMemory() const;
-  void setOnlyReadsMemory(bool onlyReadsMemory = true);
-
-  /// @brief Determine if the call cannot return.
-  bool doesNotReturn() const;
-  void setDoesNotReturn(bool doesNotReturn = true);
-
-  /// @brief Determine if the call cannot unwind.
-  bool doesNotThrow() const;
-  void setDoesNotThrow(bool doesNotThrow = true);
-
-  /// getType - Return the type of the instruction that generated this call site
-  ///
-  const Type *getType() const { return getInstruction()->getType(); }
-
   /// isCall - true if a CallInst is enclosed.
   /// Note that !isCall() does not mean it is an InvokeInst enclosed,
   /// it also could signify a NULL Instruction pointer.
@@ -109,18 +82,13 @@ public:
   ///
   bool isInvoke() const { return getInstruction() && !I.getInt(); }
 
-  /// getInstruction - Return the instruction this call site corresponds to
-  ///
-  Instruction *getInstruction() const { return I.getPointer(); }
-
-  /// getCaller - Return the caller function for this call site
-  ///
-  Function *getCaller() const { return getInstruction()
-                                  ->getParent()->getParent(); }
+  InstrTy *getInstruction() const { return I.getPointer(); }
+  InstrTy *operator->() const { return I.getPointer(); }
+  operator bool() const { return I.getPointer(); }
 
   /// getCalledValue - Return the pointer to function that is being called...
   ///
-  Value *getCalledValue() const {
+  ValTy *getCalledValue() const {
     assert(getInstruction() && "Not a call or invoke instruction!");
     return *getCallee();
   }
@@ -128,8 +96,8 @@ public:
   /// getCalledFunction - Return the function being called if this is a direct
   /// call, otherwise return null (if it's an indirect call).
   ///
-  Function *getCalledFunction() const {
-    return dyn_cast<Function>(getCalledValue());
+  FunTy *getCalledFunction() const {
+    return dyn_cast<FunTy>(getCalledValue());
   }
 
   /// setCalledFunction - Set the callee to the specified value...
@@ -139,7 +107,14 @@ public:
     *getCallee() = V;
   }
 
-  Value *getArgument(unsigned ArgNo) const {
+  /// isCallee - Determine whether the passed iterator points to the
+  /// callee operand's Use.
+  ///
+  bool isCallee(value_use_iterator<UserTy> UI) const {
+    return getCallee() == &UI.getUse();
+  }
+
+  ValTy *getArgument(unsigned ArgNo) const {
     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
     return *(arg_begin()+ArgNo);
   }
@@ -152,69 +127,142 @@ public:
 
   /// Given a value use iterator, returns the argument that corresponds to it.
   /// Iterator must actually correspond to an argument.
-  unsigned getArgumentNo(Value::use_iterator I) const {
+  unsigned getArgumentNo(value_use_iterator<UserTy> I) const {
     assert(getInstruction() && "Not a call or invoke instruction!");
     assert(arg_begin() <= &I.getUse() && &I.getUse() < arg_end()
            && "Argument # out of range!");
-
     return &I.getUse() - arg_begin();
   }
 
-  /// Given an operand number, returns the argument that corresponds to it.
-  /// OperandNo must be a valid operand number that actually corresponds to an
-  /// argument.
-  unsigned getArgumentNo(unsigned OperandNo) const {
-    assert(OperandNo >= getArgumentOffset() && "Operand number passed was not "
-                                               "a valid argument");
-    return OperandNo - getArgumentOffset();
-  }
-
-  /// hasArgument - Returns true if this CallSite passes the given Value* as an
-  /// argument to the called function.
-  bool hasArgument(const Value *Arg) const;
-
   /// arg_iterator - The type of iterator to use when looping over actual
   /// arguments at this call site...
-  typedef User::op_iterator arg_iterator;
+  typedef IterTy arg_iterator;
 
   /// arg_begin/arg_end - Return iterators corresponding to the actual argument
   /// list for a call site.
-  arg_iterator arg_begin() const {
+  IterTy arg_begin() const {
     assert(getInstruction() && "Not a call or invoke instruction!");
     // Skip non-arguments
-    return getInstruction()->op_begin() + getArgumentOffset();
+    return (*this)->op_begin() + getArgumentOffset();
   }
 
-  arg_iterator arg_end() const { return getInstruction()->op_end() - getArgumentEndOffset(); }
+  IterTy arg_end() const { return (*this)->op_end() - getArgumentEndOffset(); }
   bool arg_empty() const { return arg_end() == arg_begin(); }
   unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
-
-  bool operator<(const CallSite &CS) const {
-    return getInstruction() < CS.getInstruction();
-  }
-
-  bool isCallee(Value::use_iterator UI) const {
-    return getCallee() == &UI.getUse();
-  }
-  bool isCallee(Value::const_use_iterator UI) const {
-    return getCallee() == &UI.getUse();
-  }
+  
 private:
   /// Returns the operand number of the first argument
   unsigned getArgumentOffset() const {
     if (isCall())
-      return 1; // Skip Function
+      return 1; // Skip Function (ATM)
     else
       return 0; // Args are at the front
   }
 
   unsigned getArgumentEndOffset() const {
     if (isCall())
-      return 0; // Unchanged
+      return 0; // Unchanged (ATM)
     else
       return 3; // Skip BB, BB, Function
   }
 
+  IterTy getCallee() const {
+      // FIXME: this is slow, since we do not have the fast versions
+      // of the op_*() functions here. See CallSite::getCallee.
+      //
+    if (isCall())
+      return getInstruction()->op_begin(); // Unchanged (ATM)
+    else
+      return getInstruction()->op_end() - 3; // Skip BB, BB, Function
+  }
+};
+
+/// ImmutableCallSite - establish a view to a call site for examination
+class ImmutableCallSite : public CallSiteBase<> {
+  typedef CallSiteBase<> _Base;
+public:
+  ImmutableCallSite(const Value* V) : _Base(V) {}
+  ImmutableCallSite(const CallInst *CI) : _Base(CI) {}
+  ImmutableCallSite(const InvokeInst *II) : _Base(II) {}
+  ImmutableCallSite(const Instruction *II) : _Base(II) {}
+};
+
+class CallSite : public CallSiteBase<Function, Value, User, Instruction,
+                                     CallInst, InvokeInst, User::op_iterator> {
+  typedef CallSiteBase<Function, Value, User, Instruction,
+                       CallInst, InvokeInst, User::op_iterator> _Base;
+public:
+  CallSite() {}
+  CallSite(_Base B) : _Base(B) {}
+  CallSite(CallInst *CI) : _Base(CI) {}
+  CallSite(InvokeInst *II) : _Base(II) {}
+  CallSite(Instruction *II) : _Base(II) {}
+
+  bool operator==(const CallSite &CS) const { return I == CS.I; }
+  bool operator!=(const CallSite &CS) const { return I != CS.I; }
+
+  /// CallSite::get - This static method is sort of like a constructor.  It will
+  /// create an appropriate call site for a Call or Invoke instruction, but it
+  /// can also create a null initialized CallSite object for something which is
+  /// NOT a call site.
+  ///
+  static CallSite get(Value *V) {
+    return _Base::get(V);
+  }
+
+  /// getCallingConv/setCallingConv - get or set the calling convention of the
+  /// call.
+  CallingConv::ID getCallingConv() const;
+  void setCallingConv(CallingConv::ID CC);
+
+  /// getAttributes/setAttributes - get or set the parameter attributes of
+  /// the call.
+  const AttrListPtr &getAttributes() const;
+  void setAttributes(const AttrListPtr &PAL);
+
+  /// paramHasAttr - whether the call or the callee has the given attribute.
+  bool paramHasAttr(uint16_t i, Attributes attr) const;
+
+  /// @brief Extract the alignment for a call or parameter (0=unknown).
+  uint16_t getParamAlignment(uint16_t i) const;
+
+  /// @brief Return true if the call should not be inlined.
+  bool isNoInline() const;
+  void setIsNoInline(bool Value = true);
+  
+  /// @brief Determine if the call does not access memory.
+  bool doesNotAccessMemory() const;
+  void setDoesNotAccessMemory(bool doesNotAccessMemory = true);
+
+  /// @brief Determine if the call does not access or only reads memory.
+  bool onlyReadsMemory() const;
+  void setOnlyReadsMemory(bool onlyReadsMemory = true);
+
+  /// @brief Determine if the call cannot return.
+  bool doesNotReturn() const;
+  void setDoesNotReturn(bool doesNotReturn = true);
+
+  /// @brief Determine if the call cannot unwind.
+  bool doesNotThrow() const;
+  void setDoesNotThrow(bool doesNotThrow = true);
+
+  /// getType - Return the type of the instruction that generated this call site
+  ///
+  const Type *getType() const { return (*this)->getType(); }
+
+  /// getCaller - Return the caller function for this call site
+  ///
+  Function *getCaller() const { return (*this)->getParent()->getParent(); }
+
+  /// hasArgument - Returns true if this CallSite passes the given Value* as an
+  /// argument to the called function.
+  bool hasArgument(const Value *Arg) const;
+
+  bool operator<(const CallSite &CS) const {
+    return getInstruction() < CS.getInstruction();
+  }
+
+private:
   User::op_iterator getCallee() const;
 };